Fixing apparatus

Abstract

A fixing apparatus includes a heating member, a supporting member that supports the heating member, a film slidably disposed on the heating member, and a pressing member that forms a nip portion, in collaboration with the film, through which the recording medium is conveyed. The fixing apparatus further includes a first thermally conductive member and a second thermally conductive member that are disposed between the heating member and the supporting member. The first thermally conductive member has a thermal conductivity higher than that of a substrate of the heating member. The thermal conductivity in in-plane directions of the second thermally conductive member is higher than the thermal conductivity in a thickness direction thereof. The second thermally conductive member is in contact with the heating member, and the first thermally conductive member is in contact with the second thermally conductive member.

What is claimed is: 
     
       1. A fixing apparatus that fixes a toner image formed on a recording medium, the fixing apparatus comprising:
 a heating member including a substrate and a heating resistor formed on the substrate; 
 a supporting member that supports the heating member; 
 a film slidably disposed on the heating member; and 
 a pressing member that, in collaboration with the film, forms a nip portion through which the recording medium is conveyed, 
 wherein the fixing apparatus further comprises a first thermally conductive member and a second thermally conductive member that are disposed between the heating member and the supporting member, the first thermally conductive member having a thermal conductivity higher than that of the substrate, the second thermally conductive member having a thermal conductivity in in-plane directions and a thermal conductivity in a thickness direction, the thermal conductivity in the in-plane directions being higher than the thermal conductivity in the thickness direction, and 
 wherein the second thermally conductive member is in contact with the heating member, and 
 wherein the first thermally conductive member is disposed between the second thermally conductive member and the supporting member and is in contact with the second thermally conductive member. 
 
     
     
       2. The fixing apparatus according to  claim 1 ,
 wherein the thermal conductivity in the in-plane directions of the second thermally conductive member is higher than the thermal conductivity of the first thermally conductive member. 
 
     
     
       3. The fixing apparatus according to  claim 1 ,
 wherein the thermal conductivity in the thickness direction of the second thermally conductive member is lower than the thermal conductivity of the first thermally conductive member. 
 
     
     
       4. The fixing apparatus according to  claim 1 ,
 wherein the thermal conductivity in the in-plane directions of the second thermally conductive member is 300 W/m·K or more. 
 
     
     
       5. The fixing apparatus according to  claim 1 ,
 wherein the thermal conductivity in the thickness direction of the second thermally conductive member is 10 W/m·K or less. 
 
     
     
       6. The fixing apparatus according to  claim 1 ,
 wherein a material of the second thermally conductive member is graphite. 
 
     
     
       7. The fixing apparatus according to  claim 6 ,
 wherein a material of the first thermally conductive member is a metal. 
 
     
     
       8. The fixing apparatus according to  claim 1 ,
 wherein a thickness of the second thermally conductive member is thinner than that of the first thermally conductive member. 
 
     
     
       9. The fixing apparatus according to  claim 1 ,
 wherein a thickness of the second thermally conductive member is 100 μm or less. 
 
     
     
       10. The fixing apparatus according to  claim 1 ,
 wherein the second thermally conductive member is disposed only at an end portion in a longitudinal direction of the fixing apparatus. 
 
     
     
       11. The fixing apparatus according to  claim 1 , further comprising:
 a temperature detection device that detects temperature of the heating member and is disposed so as to be in contact with the first thermally conductive member.